The processes of biological and chemical remediation of Superfund chemicals are assumed to generate products with less toxic effects. The overall objective of the Core is to test that assumption for some of the remediation strategies employed by Investigators of the Program Project. One aspect of the core will be to generate remediation products of Superfund chemicals. This will include, but not be limited to, production of samples from the reductive dechlorination of polychlorinated biphenyls (PCBs) generated by the Production Section of the Core. Concern about PCBs has arisen because of their global distribution, environmental persistence and the fact that a variety of toxic effects have been ascribed to them. Reductive dechlorination is a novel and important anaerobic microbial transformation of PCBs that has been studied extensively by investigators in this Core and elsewhere. This process removes chlorine from the biphenyl ring resulting in mixtures containing fewer and less chlorinated congeners. This transformation may result in a change in biological activity due to differences in the composition of the resultant PCB mixtures and because individual congeners probably differ in mechanism(s) of action and potency. Biodegradation products from the anaerobic dechlorination of PCBs, and other remediation products submitted to the Core, will be assayed for biological activity using a number of tests available in the laboratories of Biomedical Investigators of the Program Project. These tests include (for example) assays for effects on intercellular communication, neutrophil function, lymphocyte blastogenesis, P-450 induction, and protein kinase C activation. The activity of the remediation products in these assays will be compared to the activity of the starting Superfund chemicals. Information resulting from this testing will be valuable in modifying remediation schemes to ensure reduction of biological activity and absence of toxic byproducts. In addition, this effort represents an important link between the remediation research and the health hazards research proposed within this program project and will aid in resolving issues of Superfund concern.